Investigators looking into the deadly California bus crash that resulted in the deaths of 10 people say there is no evidence the FedEx truck that his the bus, hit the brakes and it left no skid marks on the pavement before impact.

Authorities also cannot confirm eyewitness reports that claim the FedEx truck was on fire before it hit the bus full of young teenagers, on a stretch of I-5 near Orlando, 100 miles north of Sacramento, California.

For unknown reasons, the driver of the FedEx truck — who is one of the fatalities — veered across the Interstate median, sideswiped a Nissan Altima sedan, and crashed head-on into the bus in Northern California.

Several students barely escaped being burned to death by jumping out of windows before the explosion that engulfed both vehicles.

According to a statements from the sedan’s driver, the FedEx truck was already in flames when it hit her car and later the bus, however, National Transportation Safety Board (NTSB) investigators say there is no way to determine that account and are seeking more eyewitnesses that were present at the scene of the bus crash on the California Interstate.

The bus was taking 44 students from a Southern California High School on a free tour to Humboldt State University, which some were hoping to be the first in their families to attend.

Five students, three adult chaperones — including a twin and a recently engaged couple — and both drivers died on Thursday in the fiery inferno that left the bus and truck a charred carcass.

Following the deadly bus crash in California, the NTSB is revisiting the efforts to install seat belts on buses and school buses to protect passengers.

NTSB member Mark Rosekind commented:

“The worst thing for the NTSB is to show up, know that we’ve issued recommendations from a previous accident where lives have been lost. and find out (that) if those recommendations had been closed and enacted, lives could have been saved.”

Rosekind adds that his agency has advocated for the need of emergency exits on buses, however, federal agencies have been slow to act and he hopes the tragic California bus crash will result in new safety measures being put into place.

The NTSB official also said investigators are looking into whether the FedEx driver was impaired in any way before the truck he was driving crashed into the bus. A family member identified the truck driver as Tim Evans, 32, of Elk Grove, Calif., who, according to records, had recently relieved another driver during a stop in Sacramento.

Evidence that the bus driver tried to avoid the collision were left by more than 145 feet of tire marks, according to investigators, who are analyzing data from the black box that the bus carried on board.

New heartbreaking details about the victims that perished in the deadly California bus crash are emerging. Humboldt State University chartered two more buses, which were to bring more than 500 prospective students to their campus for a three-day visit and arrived safely.